The grades on a math midterm at Covington are normally distributed with $\mu = 70$ and $\sigma = 2.0$. Luis earned a $74$ on the exam. Find the z-score for Luis's exam grade. Round to two decimal places.
Explanation: A z-score is defined as the number of standard deviations a specific point is away from the mean We can calculate the z-score for Luis's exam grade by subtracting the mean $(\mu)$ from his grade and then dividing by the standard deviation $(\sigma)$ $ { z = \dfrac{x - {\mu}}{{\sigma}}} $ $ { z = \dfrac{74 - {70}}{{2.0}}} $ ${ z \approx 2.00}$ The z-score is $2.00$. In other words, Luis's score was $2.00$ standard deviations above the mean.